SUNDAY, June 8, 2014 (HealthDay News) -- If you suffer from seasonal allergies, a number of treatments can help relieve symptoms such as sneezing and itchy eyes, the U.S. Food and Drug Administration says.

Those therapies include three newly approved under-the-tongue immunotherapy products to counter hay fever caused by certain grass pollens and short ragweed pollen. The medications -- called Grastek, Oralair and Ragwitek -- can be taken at home, but the first dose must be given in a doctor's office due to the risk of serious immune system reactions.

"These medications have the potential for dialing down the immune response to allergens, doing more than just treating the symptoms of allergies," Dr. Jay Slater, director of FDA's division of bacterial, parasitic and allergenic products, said in an agency news release.

This type of treatment, called sublingual therapy, is best started three to four months before allergy season begins in your region of the country.

Allergy shots are another immunotherapy option. These injections contain small amounts of an allergen and can decrease sensitivity to inhaled allergens. Over two to three months, patients receive weekly injections with increasingly higher doses of the allergen. After the maximum dose is reached, patients may receive monthly injections for three to five years, Slater said.

Antihistamines -- a different type of treatment for seasonal allergies -- come in many forms, including tablets and liquids.

"There are several different antihistamines. First-generation antihistamines include medications such as diphenhydramine, marketed under the brand name Benadryl. They have been available over-the-counter for a long time," Dr. Narayan Nair, a medical officer at the FDA, said in the news release.

Some antihistamines can cause drowsiness and interfere with the ability to drive or operate heavy machinery. The drowsiness can be made worse by taking sedatives or consuming alcohol, Nair said. Also, patients with chronic conditions such as glaucoma or an enlarged prostate should talk to their health care provider before taking certain antihistamines, he added.

Nasal sprays and eye drops can also be used to treat some hay fever symptoms.

"Nasal sprays can help relieve nasal symptoms but they should only be used for a limited time without talking to a health care provider. If some nasal sprays are used longer than intended they can make the congestion worse," Nair said.